Self-reported health status and mortality in a multiethnic US cohort

The authors examined the relation between self-reported health status and mortality among the following racial/ethnic groups: Native Americans, Asian/Pacific Islanders, blacks, whites, and Hispanics. They pooled 1986-1994 data from the National Health Interview Survey to obtain information on more than 700,000 cohort participants. Although fewer than 5,000 Native Americans are included in this cohort, the data provide information previously unavailable for this group. Also included are almost 17,000 Asian/Pacific Islanders, over 90,000 blacks, and over 50,000 Hispanics. The authors found strong associations between self-reported health status and both socioeconomic status and subsequent mortality. A self-report of fair or poor health was associated with at least a twofold increased risk of mortality for all racial/ethnic groups. Even after adjustment for socioeconomic status and measures of comorbidity, a significant relation was found between self-reported health status and subsequent mortality. The authors found that self-reported health status is a strong prognostic indicator for subsequent mortality for both genders and all racial/ethnic groups examined. These results emphasize the utility of using simple filter questions in population research.

Effective and safe gene therapy for colorectal carcinoma using the cytosine deaminase gene directed by the carcinoembryonic antigen promoter

We have recently isolated carcinoembryonic antigen (CEA) promoter regions consisting of 419 bp and 204 bp from CEA-producing human colorectal carcinoma (CRC). We constructed CEA419/CD and CEA204/CD retroviruses carrying the bacterial cytosine deaminase (CD) gene directed by the CEA promoter regions. pCD2 retroviruses carrying the CD gene directed by the retrovirus long terminal repeat promoter were also used. CEA419/CD or CEA204/CD retrovirus-infected CRC cells were found to be susceptible to 5-fluorocytosine (5-FC), while non-CRC cells infected with the same retroviruses were not. CD-transduced CRC xenografts in nude mice were sensitive to 5-FC treatment, resulting in arrest of tumor growth. When mice with intraperitoneally disseminated CRCs were given intraperitoneal injections of CEA419/CD retrovirus-producing cells followed by 5-FC treatment, significantly prolonged survival rates were observed compared with animals injected with pCD2 retrovirus-producing cells followed by 5-FC treatment. Importantly, bone marrow suppression was not observed in animals injected with CEA419/CD retrovirus-producing cells and 5-FC, while profound bone marrow suppression was observed in those injected with pCD2 retrovirus-producing cells and 5-FC. These results indicate that effective and safe in vivo gene therapy for advanced CRC may be feasible by transferring the CD gene controlled by the CEA promoter followed by 5-FC treatment.

[Enhancement of apoptotic sensitivity induced by UV irradiation on the p53-transducted K562 cells]

OBJECTIVE

To answer whether wild-type p53 can sensitize K562 cell apoptosis induced by UV irradiation.

METHODS

K562 cells transducted with retrovirus encoding wild-type p53 were irradiated by ultraviolet for different time and then cultured for different time. Apoptosis was detected by TDT end labelling technique, DNA fragmentation and MTT assay.

RESULTS

TDT end labelling and DNA fragmentation showed that apoptosis induced by 8 min UV-irradiation differed significantly between K562-neo and K562-p53 cells.

CONCLUSION

Wild-type p53 can enhance apoptosis induced by UV-irradiation on K562 cells.

Serum antioxidant capacity is increased by consumption of strawberries, spinach, red wine or vitamin C in elderly women

It is often assumed that antioxidant nutrients contribute to the protection afforded by fruits, vegetables, and red wine against diseases of aging. However, the effect of fruit, vegetable and red wine consumption on the overall antioxidant status in human is unclear. In this study we investigated the responses in serum total antioxidant capacity following comsumption of strawberries (240 g), spinach (294 g), red wine (300 ml) or vitamin C (1250 mg) in eight elderly women. Total antioxidant capacity was determined using different methods: oxygen radical absorbance capacity (ORAC) assay, Trolox equivalent antioxidant capacity (TEAC) assay and ferric reducing ability (FRAP) assay. The results showed that the total antioxidant capacity of serum determined as ORAC, TEAC and FRAP, using the area under the curve, increased significantly by 7-25% during the 4-h period following consumption of red wine, strawberries, vitamin C or spinach. The total antioxidant capacity of urine determined as ORAC increased (P < 0.05) by 9.6, 27.5, and 44.9% for strawberries, spinach, and vitamin C, respectively, during the 24-h period following these treatments. The plasma vitamin C level after the strawberry drink, and the serum urate level after the strawberry and spinach treatments, also increased significantly. However, the increased vitamin C and urate levels could not fully account for the increased total antioxidant capacity in serum following the consumption of strawberries, spinach or red wine. We conclude that the consumption of strawberries, spinach or red wine, which are rich in antioxidant phenolic compounds, can increase the serum antioxidant capacity in humans. J. Nutr. 2383-2390, 1998

Postprandial plasma carotenoid responses following consumption of strawberries, red wine, vitamin C or spinach by elderly women

This study investigated the postprandial plasma responses of carotenoids for 24 h after feeding five specific breakfast beverages; four of which had low or no carotenoid content. In seven fasting healthy elderly female subjects a blood sample (baseline) was obtained, after which they were given a breakfast beverage, containing one of the following: 1) strawberries (240 g); 2) ascorbic acid (1250 mg); 3) spinach (294 g); 4) red wine (300 mL); and 5) control (breakfast beverage only). Blood samples were collected at 0.5, 1, 4, 7, 11, 15 and 24 h. Plasma carotenoids were measured using HPLC. No significant differences were found in the levels of the plasma carotenoids measured among the various treatments at baseline. In the spinach treatment, plasma lutein, zeaxanthin and beta-carotene levels at 7, 11, 15 and 24 h were significantly higher than those at baseline, as expected. All of the carotenoids measured in the control and vitamin C treatments, at subsequent sampling times were not significantly different from those at baseline. However, for most carotenoids, strawberry and red wine feeding resulted in significantly lower carotenoids values from baseline at 11 and 15 h. Subjects who received a diet with low levels of carotenoids, but whose postprandial plasma levels of carotenoids remain steady, might be explained by a mechanism that promotes secretion of carotenoids into the circulation. Assuming that plasma carotenoids are being used over time, we hypothesize that strawberries and red wine contain some substances that interfere with the secretion of carotenoids into the circulation.

Membrane and receptor modifications of oxidative stress vulnerability in aging. Nutritional considerations

Evidence suggests that oxidative stress (OS) may contribute to the pathogenesis of age-related decrements in neuronal function and that OS vulnerability increases as a function of age. In addition to decreased endogenous protection, increases in OS vulnerability may result from changes in membrane lipids and distribution of receptor subtype. Using a PC-12 cell model system, we have shown that H2O2 or dopamine (DA) exposure induced deficits in the cell's ability to clear (extrude/sequester, E/S) Ca2+ that are similar to those seen in aging. When plasma membrane concentrations of sphingomyelin (SPM) were used, the SPM metabolite, sphingosine-1-phosphate was increased to the same levels as those seen in aging, and enhancement of OS-induced decreases in calcium E/S following KCL depolarization was observed. Differential decreases in CA2+ E/S were also seen following DA-induced OS in COS-7 cells transfected with one of five muscarinic receptor subtypes. Cells transfected with either M1, M2, or M4 receptors showed significantly greater vulnerability to OS (as expressed by greater decrements in calcium E/S and cell death) than those transfected with M3 or M5 receptors. The vitamin E analogue, Trolox, and the nitrone-trapping agent, PBN, were not effective in altering E/S decrements but were effective in preventing cell death 24 h after OS exposure. These findings suggest that putative regional (e.g., striatum and hippocampus) increases in OS vulnerability and loss of neuronal function in aging may be dependent upon membrane SPM concentration and receptor subtype. In related studies, attempts were made to determine whether increased OS protection via nutritional increases in antioxidant levels in rats [using diets supplemented with vitamin E (500IU/kg), strawberry extracts (9.4 g/kg dried aqueous extract, DAE), spinach (6.7 g/kg DAE), or blueberry extracts (10 g/kg DEA for six weeks)] would protect against exposure to 100% O2 (a model of accelerated neuronal aging). Results indicated that these diets were effective in preventing OS-induced decrements in several parameters (e.g., nerve growth factor decreases), suggesting that although there may be increases in OS vulnerability in aging, phytochemicals present in antioxidant-rich foods may be beneficial in reducing or retarding the functional central nervous system deficits seen in aging or oxidative insult.

The effect of long-term dietary supplementation with antioxidants

The impact of diet and specific food groups on aging and age-associated degenerative diseases has been widely recognized in recent years. The modern concept of the free radical theory of aging takes as its basis a shift in the antioxidant/prooxidant balance that leads to increased oxidative stress, dysregulation of cellular function, and aging. In the context of this theory, antioxidants can influence the primary "intrinsic" aging process as well as several secondary age-associated pathological processes. For the latter, several epidemiological and clinical studies have revealed potential roles for dietary antioxidants in the age-associated decline of immune function and the reduction of risk of morbidity and mortality from cancer and heart disease. We reported that long-term supplementation with vitamin E enhances immune function in aged animals and elderly subjects. We have also found that the beneficial effect of vitamin E in the reduction of risk of atherosclerosis is, in part, associated with molecular modulation of the interaction of immune and endothelial cells. Even though the effects of dietary antioxidants on aging have been mostly observed in relation to age-associated diseases, the effects cannot be totally separated from those related to the intrinsic aging process. For modulation of the aging process by antioxidants, earlier reports have indicated that antioxidant feeding increased the median life span of mice to some extent. To further delineate the effect of dietary antioxidants on aging and longevity, middle-aged (18 mo) C57BL/6NIA male mice were fed ad libitum semisynthetic AIN-76 diets supplemented with different antioxidants (vitamin E, glutathione, melatonin, and strawberry extract). We found that dietary antioxidants had no effect on the pathological outcome or on mean and maximum life span of the mice, which was observed despite the reduced level of lipid peroxidation products, 4-hydroxynonenol, in the liver of animals supplemented with vitamin E and strawberry extract (1.34 +/- 0.4 and 1.6 +/- 0.5 nmol/g, respectively) compared to animals fed the control diet (2.35 +/- 1.4 nmol/g). However, vitamin E-supplemented mice had significantly lower lung viral levels following influenza infection, a viral challenge associated with oxidative stress. These and other observations indicate that, at present, the effects of dietary antioxidants are mainly demonstrated in connection with age-associated diseases in which oxidative stress appears to be intimately involved. Further studies are needed to determine the effect of antioxidant supplementation on longevity in the context of moderate caloric restriction.

Scavenger receptor, class B, type I-dependent stimulation of cholesterol esterification by high density lipoproteins, low density lipoproteins, and nonlipoprotein cholesterol

Scavenger receptor, class B, type I (SR-BI) is a cell surface glycoprotein that mediates selective uptake and efflux of sterols from high density lipoproteins (HDL) to cells. A Chinese hamster ovary cell line that is deficient in functional LDL receptors, but has high expression levels of recombinant SR-BI (ldlA7-SR-BI), was used to examine the effect of SR-BI on the trafficking of sterols between lipoproteins and cells. To monitor the fate of sterols transported by SR-BI into cells, we measured the incorporation of [14C]oleate into cholesterol esters by acyl-CoA:cholesteryl acyltransferase in the endoplasmic reticulum. We show that incubation of ldlA7-SRBI cells with either LDL or HDL resulted in an equally dramatic increase in the formation of [14C]oleate-labeled cholesterol esters. The lipoprotein-stimulated, SR-BI-dependent increase in cholesterol esterification was inhibited by chloroquine. The uptake of sterols and their incorporation into cholesterol esters by SR-BI from LDL was largely a selective process. The addition of free cholesterol to ldlA7-SRBI cells also stimulated cholesterol ester formation in a chloroquine-sensitive fashion. We also show that SR-BI mediates the efflux of endogenously synthesized sterols from the cell membrane. From these studies we conclude that, in the absence of the LDL receptor, overexpression of SR-BI can mediate significant transport of sterols between lipoproteins and the endoplasmic reticulum of cells.

Increases in human plasma antioxidant capacity after consumption of controlled diets high in fruit and vegetables

BACKGROUND

The putative beneficial effects of an increased consumption of fruit and vegetables have been associated with antioxidant nutrients. However, the effect of fruit and vegetable consumption on the overall antioxidant status in humans is unclear.

OBJECTIVE

The objective of this study was to investigate whether a diet rich in fruit and vegetables would affect the antioxidant capacity of human plasma.

DESIGN

Thirty-six healthy nonsmokers resided in a metabolic research unit and consumed 2 sets of controlled diets. Diet A contained 10 servings of fruit and vegetables each day for 15 d. Diet B was the same as diet A, except diet B also provided 2 servings of broccoli each day on days 6-10. There was a free-living period of a minimum of 6 wk between the 2 experiments using either diet A or diet B. Fasting plasma antioxidant capacity, measured as oxygen radical absorbance capacity (ORAC), and alpha-tocopherol concentrations were determined on days 1, 6, 11, and 16.

RESULTS

The fasting baseline plasma ORAC of these subjects was significantly correlated with their estimated daily intake of total antioxidants from fruit and vegetables during the previous year. Plasma ORAC of these subjects was significantly increased by both diets A and B. This increase in ORAC could not be explained by the increase in the plasma alpha-tocopherol concentration.

CONCLUSION

Increased consumption of fruit and vegetables can increase the plasma antioxidant capacity in humans.

Pharmacokinetic interaction between ritonavir and indinavir in healthy volunteers

The pharmacokinetic interaction between indinavir and ritonavir was evaluated in five groups of healthy adult volunteers to explore the potential for twice-daily (b.i.d.) dosing of this combination. All subjects received 800 mg of indinavir every 8 h (q8h) on day 2. In addition, subjects in group I received one dose of 800 mg of indinavir on day 1 and 800 mg of indinavir q8h on day 17. Subjects in Groups II and IV each received one dose of 600 mg of indinavir on days 1 and 17, and subjects in groups III and V each received one dose of 400 mg of indinavir on days 1 and 17. During days 3 to 17, ritonavir placebo or ritonavir at 200, 300, 300, or 400 mg q12h was given to groups I, II, III, IV, and V, respectively. Ritonavir at steady state probably inhibited the cytochrome P-450 3A metabolism of indinavir and substantially increased plasma indinavir concentrations, with the area under the plasma concentration-time curve (AUC) increasing up to 475% and the peak concentration in serum (Cmax) increasing up to 110%. The Cmax/trough concentration ratio decreased from 50 in standard q8h regimens to less than 14 when indinavir was administered with ritonavir. For a constant indinavir dose, an increase in the ritonavir dose yielded similar indinavir AUCs, Cmaxs, and concentrations at 12 h (C12s). For a constant ritonavir dose, an increase in the indinavir dose resulted in approximately proportional increases in the indinavir AUC, less than proportional increases in Cmax, and slightly more than proportional increases in C12. Ritonavir reduced between-subject variability in the indinavir AUC and trough concentrations and did not affect indinavir renal clearance. With the altered pharmacokinetic profile, indinavir likely could be given as a b.i.d. combination regimen with ritonavir. This could potentially improve patient compliance and thereby reduce treatment failures.

Comparison of carcinoembryonic antigen promoter regions isolated from human colorectal carcinoma and normal adjacent mucosa to induce strong tumor-selective gene expression

To establish in vivo gene therapy against cancer, it is requisite to induce strong, cancer cell-selective expression of a therapeutic gene. Comparison of the promoter activity of 5' flanking regions of the carcinoembryonic antigen (CEA) gene isolated from various origins is therefore of considerable interest. The 5' flanking region of the CEA gene between -135 and +69 bp upstream from the transcriptional start site, which is recognized as the core promoter region, was isolated from CEA-producing human colorectal carcinoma (CRC), normal adjacent mucosa, CEA-producing cell lines and CEA-non-producing cell lines. No mutations were observed by single-strand conformation polymorphism in the CEA promoter regions. Subsequent sequence analysis revealed that there were no mutations in the CEA promoter regions isolated from CEA-producing CRC and normal adjacent mucosa. Furthermore, nuclear extracts prepared from CEA-producing human CRC cells could equally bind to both the CEA promoter fragments isolated from CEA-producing CRC and normal mucosa. Both CEA promoter regions could direct 5- to 20-fold higher expression of a luciferase reporter gene in CEA-producing cells than in CEA-non-producing cells. Therefore, we suggest that the use of either CEA promoter region isolated from CRC or normal mucosa is equally effective to induce strong, CEA-producing cancer-selective expression of a therapeutic gene.

Comparison of carcinoembryonic antigen promoter regions isolated from human colorectal carcinoma and normal adjacent mucosa to induce strong tumor-selective gene expression

To establish in vivo gene therapy against cancer, it is requisite to induce strong, cancer cell-selective expression of a therapeutic gene. Comparison of the promoter activity of 5' flanking regions of the carcinoembryonic antigen (CEA) gene isolated from various origins is therefore of considerable interest. The 5' flanking region of the CEA gene between -135 and +69 bp upstream from the transcriptional start site, which is recognized as the core promoter region, was isolated from CEA-producing human colorectal carcinoma (CRC), normal adjacent mucosa, CEA-producing cell lines and CEA-non-producing cell lines. No mutations were observed by single-strand conformation polymorphism in the CEA promoter regions. Subsequent sequence analysis revealed that there were no mutations in the CEA promoter regions isolated from CEA-producing CRC and normal adjacent mucosa. Furthermore, nuclear extracts prepared from CEA-producing human CRC cells could equally bind to both the CEA promoter fragments isolated from CEA-producing CRC and normal mucosa. Both CEA promoter regions could direct 5- to 20-fold higher expression of a luciferase reporter gene in CEA-producing cells than in CEA-non-producing cells. Therefore, we suggest that the use of either CEA promoter region isolated from CRC or normal mucosa is equally effective to induce strong, CEA-producing cancer-selective expression of a therapeutic gene.

Long-term dietary strawberry, spinach, or vitamin E supplementation retards the onset of age-related neuronal signal-transduction and cognitive behavioral deficits

Recent research has indicated that increased vulnerability to oxidative stress may be the major factor involved in CNS functional declines in aging and age-related neurodegenerative diseases, and that antioxidants, e.g., vitamin E, may ameliorate or prevent these declines. Present studies examined whether long-term feeding of Fischer 344 rats, beginning when the rats were 6 months of age and continuing for 8 months, with diets supplemented with a fruit or vegetable extract identified as being high in antioxidant activity, could prevent the age-related induction of receptor-mediated signal transduction deficits that might have a behavioral component. Thus, the following parameters were examined: (1) oxotremorine-enhanced striatal dopamine release (OX-K+-ERDA), (2) cerebellar beta receptor augmentation of GABA responding, (3) striatal synaptosomal 45Ca2+ clearance, (4) carbachol-stimulated GTPase activity, and (5) Morris water maze performance. The rats were given control diets or those supplemented with strawberry extracts (SE), 9.5 gm/kg dried aqueous extract (DAE), spinach (SPN 6.4 gm/kg DAE), or vitamin E (500 IU/kg). Results indicated that SPN-fed rats demonstrated the greatest retardation of age-effects on all parameters except GTPase activity, on which SE had the greatest effect, whereas SE and vitamin E showed significant but equal protection against these age-induced deficits on the other parameters. For example, OX-K+-ERDA enhancement was four times greater in the SPN group than in controls. Thus, phytochemicals present in antioxidant-rich foods such as spinach may be beneficial in retarding functional age-related CNS and cognitive behavioral deficits and, perhaps, may have some benefit in neurodegenerative disease.

[Enhancement of Vp16 inducing apoptosis of leukemic cells by retrovirus-mediated bcl-2 anti-sense RNA]

OBJECTIVE

To explore the effects of retrovirus-mediated bcl-2 antisense RNA on apoptosis of leukemic cells.

METHODS

Retrovirus was packaged in vitro with PA317 cells and Jurkat cell was transducted with collected virus; The expressions of bcl-2 mRNA and protein were assayed by RT-PCR and Western blotting, respectively. Apoptosis was assayed by flow cytometry and DNA "ladder".

RESULTS

Expression of intrinsic bcl-2 was decreased, and the sensitivity of leukemic cells to Vp16 and the apoptosis of leukemic cells line Jurkat cells were enhanced by transfected bcl-2 antisense RNA.

CONCLUSION

Antisense bcl-2 enhances Vp16 inducing apoptosis of leukemic cells. The results provide a useful experimental basis for leukemia therapy.

Age-related neurodegeneration and oxidative stress: putative nutritional intervention

This review describes age-related changes that occur in neuronal function and cites evidence to show that these alterations may be the result of increased sensitivity to oxidative stress (OS). Evidence is presented to show that the abilities to mitigate the OS effects and to repair the damage from OS show decline as a function of age. Results from age- and OS-sensitive tests are given; these results indicate that one of the major sites of action of OS is the membranes, especially if compromised by high amounts of sphingomyelin, and one of the major effects of OS is to further alter the calcium disregulation in aging. It is suggested that attempts to increase antioxidant protection through diets comprised of fruits and vegetables identified as being high in total antioxidant activity might prevent or reverse the deleterious OS effects on neuronal aging.

Disease incidence and longevity are unaltered by dietary antioxidant supplementation initiated during middle age in C57BL/6 mice

The ability of augmented antioxidant consumption to alter disease incidence, lesion burden and/or longevity was studied in adult male C57BL/6 mice. Mice were fed modified AIN76 diet or modified AIN76 supplemented with vitamin E, glutathione (GSH), vitamin E and GSH, melatonin or strawberry extract starting at 18 months of age. All the mice in this study were heavier than reference populations of male C57BL/6 mice fed NIH-07 or NIH-31, which were maintained without a mid-life change in diet. Fatty liver, focal kidney atrophy and proteinacious casts in the renal tubules were observed more frequently in this study population than in the reference populations. Lesion burden and incidence of specific lesions observed amongst the various groups in this study did not differ. There were no differences observed for longevity of any of the study groups. The longevity observed in this study was similar to that previously reported for male C57BL/6 mice. Thus, diet supplementation with antioxidants initiated during middle age did not appear to affect age-associated lesions patterns, lesion burden or longevity for ad libitum fed male C57BL/6 mice.

Comparison of different analytical methods for assessing total antioxidant capacity of human serum

Three assays were compared for the determination of total antioxidant capacity in human serum: the oxygen radical absorbance capacity (ORAC) assay, the Randox Trolox-equivalent antioxidant capacity (Randox-TEAC) assay, and the ferric reducing ability (FRAP) assay. There was a weak but significant linear correlation between serum ORAC and serum FRAP. There was no correlation either between serum ORAC and serum TEAC or between serum FRAP and serum TEAC. The effect of dilution on the serum TEAC value and the use of inhibition percentage at a fixed time, without considering the length of inhibition time in the quantitation of results, adversely affected the Randox-TEAC assay. The FRAP assay is simple and inexpensive but does not measure the SH-group-containing antioxidants. The ORAC assay has high specificity and responds to numerous antioxidants. By utilizing different extraction techniques in the ORAC assay, one can remove serum proteins and also make some gross differentiation between aqueous and lipid-soluble antioxidants. However, the ORAC assay requires approximately 60 min more than the FRAP or Randox-TEAC assay to quantitate results.

[Endovascular exclusion of abdominal aortic aneurysm]

OBJECTIVE

To explore the indications, methods, manipulations, and problems of endovascular exclusion of abdominal aortic aneurysm (AAA).

METHOD

Under general anesthesia and dynamic supervision of DSA, an endovascular exclusion with a stent-graft complex of 11.0 cm x 2.6 cm was successfully performed on a 70-year-old man contraindicated for major open surgery with AAA of 10.0 cm x 6.0 cm and an AAA neck of 2.5 cm x 1.6 cm.

RESULT

The patient was up and about on the first postoperative day. Duplex scan (by the end of the first postoperative week) and CT (on the postoperative 20th day) revealed a completely excluded AAA by the stent-graft that was patent and had an inner diameter of 2.2-2.4 cm, without migration and torsion. The primary AAA sac was full of thrombi and no patent lumbar and inferior mesenteric arteries were observed. The external diameter of AAA was unchanged, renal and iliac arteries were all patent, but a micro-crevice between the proximal end of the stent-graft and the anterior wall of the AAA neck was revealed. Six months postoperative follow-up showed that the patient's abdominal pulsatile mass and the left lower extremity's claudication disappeared.

CONCLUSION

Endovascular exclusion of AAA is of great practical value.

Pharmacokinetic interactions between two human immunodeficiency virus protease inhibitors, ritonavir and saquinavir

OBJECTIVE

To assess the pharmacokinetic interaction between ritonavir and saquinavir.

METHODS

Ritonavir and saquinavir were administered in single doses to six groups of healthy volunteers in a two-way (saquinavir alone and ritonavir plus saquinavir for groups I through V) and a three-way (ritonavir alone, saquinavir alone, and ritonavir plus saquinavir for group VI) crossover manner with the following doses: group I, 200 mg saquinavir and 300 mg ritonavir; group II, 200 mg saquinavir and 600 mg ritonavir; group III, 400 mg saquinavir and 300 mg ritonavir; group IV, 400 mg saquinavir and 600 mg ritonavir; group V; 600 mg saquinavir and 200 mg ritonavir; group VI, 600 mg saquinavir and 600 mg ritonavir.

RESULTS

Coadministration of ritonavir markedly increased the area under the plasma concentration-time curve (AUC) and peak concentration of saquinavir (> 50-fold and 22-fold, respectively). For a constant ritonavir dose, the pharmacokinetics of saquinavir were relatively proportional to dose. For a constant saquinavir dose, the increase in saquinavir concentration tended to be less than proportional to ritonavir dose. Ritonavir reduced intersubject variability in the saquinavir AUC from 60% to 28%. The in vivo inhibition constant was 0.025 +/- 0.020 micrograms/ml with noncompartmental estimation and 0.0164 +/- 0.0004 micrograms/ml with nonlinear mixed-effects model compartmental analysis. Saquinavir showed no clinically significant effect on the pharmacokinetics of ritonavir (+6.4% in AUC). The regimens were well tolerated.

CONCLUSIONS

The large effect of ritonavir on the pharmacokinetics of saquinavir is consistent with a large reduction of saquinavir first-pass metabolism and postabsorptive clearance. Given the limited bioavailability of saquinavir given in the hard gelatin capsule formulation, this drug interaction is expected to have implications in the use of protease inhibitors in the management of human immunodeficiency virus infection.

Lack of CYP3A inhibition effects of sertindole on terfenadine in healthy volunteers

The effect of sertindole (a new selective antipsychotic compound) on the pharmacokinetic disposition of terfenadine was investigated. Thirteen subjects who completed the study received a single 120 mg dose of terfenadine alone or with concomitant 20 mg sertindole daily. The mean values for terfenadine Cmax (alone: 2.42 +/- 1.48 ng/ml, in combination: 2.99 +/- 1.85 ng/ml) and AUC (29.6 +/- 18.9 vs 37.9 +/- 23.4 ng x hr/ml) did not change statistically significant in the presence of sertindole (p > 0.05). Similarly, the mean Cmax (531 +/- 195 vs 506 +/- 190 ng/ml) and AUC (3,728 +/- 1,163 vs 4,003 +/- 1,739 ng x hr/ml) values of carboxyterfenadine did not change statistically significant in the presence of sertindole (p > 0.05). The other pharmacokinetic parameters of terfenadine and carboxyterfenadine such as Tmax, t1/2, as well as the carboxyterfenadine to terfenadine Cmax and AUC ratios did not change in the presence of sertindole. Although terfenadine is a substrate for CYP3A (cytochrome P-450 3A), while sertindole is a substrate for both CYP2D6 and CYP3A4, the results in this study suggest that sertindole, at a clinical dose, is not an inhibitor of the metabolism of terfenadine.

Mortality patterns among adult Hispanics: findings from the NHIS, 1986 to 1990

OBJECTIVES

The purpose of this study was to assess the mortality pattern of the adult Hispanic population in the United States.

METHODS

This was a cohort study using data from the National Health Interview Survey from 1986 through 1990. Deaths were ascertained by matching the National Death Index through 1991.

RESULTS

This representative national sample included 297,640 non-Hispanic Whites, 53,552 Blacks, and 27,239 Hispanics, all aged 18 years or older at baseline. Different matching criteria resulted in modest differential estimates of the number of deaths by ethnic groups; these differences were quantitatively more important for Hispanics. Overall age-standardized mortality was lower among Hispanics. A prominent age by race interaction was apparent. The Hispanic: White mortality ratio was 1.33, 0.92, and 0.76 among men aged 18 through 44, 45 through 64, and 65 and older, respectively. Among women in the same age groups the Hispanic: White mortality ratio was 1.22, 0.75, and 0.70, respectively.

CONCLUSIONS

Longitudinal cohorts provide an important source of health status information on Hispanics. These results suggest that overall mortality is lower among Hispanics than among non-Hispanic Whites, especially in the oldest age group. Among younger and middle-aged persons, the mortality of Hispanics is similar to or even higher than that of Whites.

[A comparative study on transabdominal versus retroperitoneal approach for abdominal aortic surgery]

OBJECTIVE

To retrospectively compare transabdominal with retroperitoneal approach to the aorta for infrarenal aortic reconstruction.

METHODS

From January 1988 to December 1996, Patients undergoing surgery for abdominal aortic aneurysm (AAA) or aortoiliac occlusive disease (AIOD) were included in the retrospective comparison of transabdominal approach (TAA) with retroperitoneal approach (RPA) for aortic surgery. Forty-four patients were analyzed, with 26 (23 with AAA and 3 with AIOD) in TAA group and 18 (16 with AAA and 2 with AIOD) in RPA group. There were no significant differences between the groups in terms of age, sex, comorbid conditions, and vascular graft anastomoses.

RESULTS

The incidence of intraoperative complications was similar for both groups. Postoperatively, RPA group had significantly fewer overall complications than TAA group (P < 0.01). The incidence of prolonged ileus (6 cases in TAA group, none in RPA group) and small bowel obstruction (2 cases in TAA group, none in RPA group) was higher in the TAA group (P < 0.01). Postoperatively four deaths occurred with two in each group. There was no difference in pulmonary complications (P = 0.70). In long-term follow-up (mean 32 months), no significant difference was found in incisional hernias in the two groups.

CONCLUSIONS

RPA approach, with fewer postoperative complications, short stay in the hospital and intensive care unit, is a safer and simpler approach for abdominal aortic surgery.

Structure and localization of the human gene encoding SR-BI/CLA-1. Evidence for transcriptional control by steroidogenic factor 1

The scavenger receptor, class B, type 1 receptor (SR-BI) mediates the selective transport of lipids from high density lipoprotein to cells. We describe the structure and subchromosomal location of human SR-BI and provide evidence that it is regulated by the transcription factor, steroidogenic factor 1 (SF-1). SR-BI resides on chromosome 12q24.2-qter, spans approximately 75 kilobase pairs, and contains 13 exons. RNA blot analysis of human tissues reveals an expression pattern similar to that described previously for rodents with the highest levels of mRNA in the adrenal gland, ovary, and liver. Unlike rodents, human SR-BI was expressed at high levels in the placenta. The transcription start site for SR-BI was mapped, and DNA sequence analysis revealed a binding site for SF-1 in the proximal 5'-flanking sequence. SF-1, an orphan member of the nuclear hormone receptor gene family, plays a key role in the regulation of steroidogenesis and is expressed at high levels in steroidogenic tissues. SF-1 binds to the SR-BI promoter in a sequence-specific manner, and efficient transcription from this promoter in adrenocortical Y1 cells is dependent on an intact SF-1 site. These data extend our understanding of SF-1 function within steroidogenic tissues and suggest that SR-BI, which serves to supply selected tissues with lipoprotein-derived lipids, is part of the repertoire of SF-1-responsive genes involved in steroidogenesis.

[ICAM-1 mRNA expression in the bronchial tissue of asthmatic guinea pigs]

To determine the expression of ICAM-1 mRNA in the bronchial tissue of asthmatic guinea pigs. The guinea pigs were divided randomly in to asthma, asthma treated with dexamethasone (DEX), and control groups. ICAM-1 expression was analyzed by in situ hybridization and the cellular infiltrate was evaluated by HE staining. In situ hybridization demonstrated ICAM-1 mRNA was mainly expressed in the cytoplasm of epithelial cells and endothelial cells. Compared with the control and DEX groups, a significant increase of ICAM-1 mRNA expression was observed in the bronchial tissue (P < 0.02 and 0.05 respectively). In asthmatic guinea-pigs, the intensity of ICAM-1 mRNA expression in bronchial tissue was correlated with total leucocyte infiltrate (P < 0.05). ICAM-1 expression in bronchial tissue may be related with the leucocyte infiltration and glucocorticoid may inhibit the expression of cell adhesion molecules.

The effect of erythromycin on the CYP3A component of sertindole clearance in healthy volunteers

The effect of erythromycin on the pharmacokinetic disposition of oral sertindole, a new antipsychotic compound, was investigated. Ten subjects who completed the study received a single 4-mg dose of sertindole without or with concomitant erythromycin 250 mg taken orally 4 times daily. Coadministration of sertindole and erythromycin led to a 33% decrease (P < 0.05) in mean (+/- SD) time to reach maximum plasma concentration (tmax) value and a 15% elevation (P < 0.05) in the mean maximum plasma concentration (Cmax) value of sertindole. The mean area under the concentration-time curve (AUC) value of sertindole did not change significantly in the presence of erythromycin (alone: 159 +/- 111 ng.hr/mL, in combination: 179 +/- 144 ng.hr/mL, P > 0.05). The presence of erythromycin also significantly increased the dehydrosertindole Cmax and AUC means by 16% and 21%, respectively, possibly due to inhibition of the CYP3A metabolic isozyme responsible for the elimination of this metabolite. The rate of absorption of sertindole and the rate of appearance of dehydrosertindole in the systemic circulation after a 4-mg sertindole single dose were slightly enhanced by concomitant dosing of erythromycin. In conclusion, there is a small but noticeable effect of erythromycin on the pharmacokinetic disposition of sertindole. The effects are believed to have little clinical significance.

Mortality from coronary heart disease and cardiovascular disease among adult U.S. Hispanics: findings from the National Health Interview Survey (1986 to 1994)

OBJECTIVES

We sought to estimate the coronary heart disease (CHD) and cardiovascular disease (CVD) mortality experience of U.S. Hispanics.

BACKGROUND

Limited information is available concerning the mortality from CHD among U.S. Hispanics, the nation's second largest minority group.

METHODS

The study used data from the National Health Interview Survey (1986 to 1994), including representative national samples of 246,239 non-Hispanic whites, 38,042 blacks and 14,965 Hispanics who were > or = 45 years old at baseline. Mean follow-up of mortality was 5 years (range 1 to 10).

RESULTS

During the follow-up period, 27,702 whites (11%), 4,976 blacks (13%) and 1,061 Hispanics (7%) died. Among men, the age-adjusted total mortality per 100,000 person-years was 3,089 in whites and 2,466 in Hispanics, and among women, it was 1,897 and 1,581 in whites and Hispanics, respectively. The Hispanic/white mortality rate ratio for CHD was 0.77 (95% confidence interval [CI] 0.64 to 0.93) and 0.82 (95% CI 0.66 to 1.01) for men and women, respectively. The rate ratio was 0.79 (95% CI 0.68 to 0.91) and 0.80 (95% CI 0.69 to 0.94), respectively, for mortality from cardiovascular diseases. Given the lower all-cause mortality in Hispanics, the proportion of total deaths due to CHD and CVD was similar between the two populations for the same gender and were, respectively, 29.7% and 44.7% in white men, 28.1% and 44.3% in Hispanic men, 24.9% and 43.2% in white women and 24.1% and 41% in Hispanic women.

CONCLUSIONS

These data from a cohort of a large national sample are consistent with vital statistics that show that all-cause, CHD and CVD mortality is approximately 20% lower among adult Hispanics than among whites in the United States.

Population analysis of the pharmacokinetics and pharmacodynamics of seratrodast in patients with mild to moderate asthma

BACKGROUND

Seratrodast, a potent thromboxane receptor antagonist, is approved in Japan for the treatment of asthma and currently is being developed in the United States.

METHODS

This was a phase II, randomized, double-blind, parallel-group, placebo-controlled 15-center study of seratrodast in patients with mild to moderate asthma. A total of 183 patients were randomly assigned to receive daily doses of either placebo, or 80 mg seratrodast, or 120 mg seratrodast for 8 weeks. Pharmacokinetic and pharmacodynamic modeling was carried out by means of the population approach. A two-compartment model with zero-order input and first-order elimination best fitted the plasma concentration-time data.

RESULTS AND CONCLUSIONS

The pharmacokinetics of seratrodast were linear after single and multiple dosing for 8 weeks. The population estimates for oral clearance and apparent volume of distribution were 8.5 ml/hr/kg and 43.3 ml/kg, respectively. All pharmacokinetic parameters (the oral central compartment clearance, the volumes of distribution of the central and peripheral compartments, and the intercompartmental clearance) were estimated with a precision of 10% or less and were found to be associated with body weight. The residual variability was 30%. The values of oral clearance estimated in this study in male patients were similar to those previously estimated in healthy male subjects. Seratrodast at a dose of 120 mg daily produced an increase in forced expiratory volume in 1 second (FEV1) from baseline that was linearly correlated with its plasma concentrations. The average slope of the concentration-effect relationship was 0.222% and 0.470% per microgram/ml after single and multiple dosing, respectively. Interpatient variability in response was mainly affected by the initial severity of the disease. A lower percentage of predicted FEV1 (i.e., more severe obstruction) was associated with higher slopes, and greater increases in FEV1.

Evaluation of the effect of fluconazole on the pharmacokinetics of ritonavir

The effects of fluconazole on the pharmacokinetics of the HIV protease inhibitor ritonavir were investigated after multiple dosing in an open-label study. In this randomized, two-period crossover study, eight healthy subjects received ritonavir alone (200 mg every 6 hr for 4 days) and ritonavir with fluconazole (400 mg on day 1, 200 mg every day on days 2-5) with a 2-week washout period. Ritonavir plasma concentrations were measured during the final four ritonavir dosing intervals (24 hr) and a 12-hr washout period. There were statistically significant increases in ritonavir C(max) and AUC0-24 (p < 0.02), with concurrent administration of fluconazole compared with administration of ritonavir alone. The difference between regimens in C(min) was marginally statistically significant (p = 0.089), and t(max) and beta were not statistically significantly different. Although some ritonavir parameters were affected by fluconazole, mean increases in C(max) and AUC were < or = 15% for the 24-hr period, and only 7-19% for individual dose intervals. Thus, the pharmacokinetics of ritonavir may be influenced only to a small extent when administered with fluconazole. These changes are probably of limited clinical significance and do not necessitate dosage adjustment of ritonavir when fluconazole is added to the regimen.

Pharmacokinetics of sertindole in healthy young and elderly male and female subjects

OBJECTIVE

The pharmacokinetic disposition of oral sertindole, a new selective antipsychotic compound, in young and elderly male and female subjects was investigated.

STUDY DESIGN

A total of 46 subjects (12 young males, 11 elderly males, 11 young females, and 12 elderly females) received 4 mg/day sertindole (once a day; days 1 through 3) for 3 consecutive days, 8 mg/day sertindole for 3 consecutive days (days 4 through 6), and 12 mg/day sertindole for 10 consecutive days (days 7 through 16).

RESULTS

Age and gender did not appear to have any effect on the plasma binding of sertindole, despite a lower albumin concentration in elderly subjects. After multiple dosing of 12 mg sertindole, the mean peak plasma concentration (Cmax) values for young and elderly female subjects were 20% and 31% higher than those observed for male subjects of comparable age (p < 0.05). The mean values for area under the plasma concentration-time curve [AUC(0-24)] of female subjects were 29% higher than those observed in male subjects of similar age (p < 0.05). There were no statistically significant age-related differences in Cmax and AUC(0-24) (or apparent total plasma clearance), and there were no gender- or age-related differences for the elimination rate constant or values for apparent volume of distribution during the terminal elimination phase after the last 12 mg dose on day 16 (p > 0.05).

CONCLUSIONS

There are no differences between young and elderly subjects in the absorption and elimination of sertindole. The higher Cmax and AUC values in females may be a result of a higher extent of absorption or a dependence of sertindole clearance on lean body mass.

Optically heterodyned 25-GHz true-time-delay lines on thick LD-3 polymer-based planar waveguides

Synthesis of the LD-3 electro-optic polymer has resulted in a highly reliable nonlinear organic material. Such a success has been impeded from further progress because the LD-3 films produced thus far are too thin (<0.5 mum) to form a waveguide. Further details of material synthesis have to be studied to solve this problem. We report the formation of thick LD-3 films ranging from 1.2 to 2.4 mum by introducing cyclopentanone as the new solvent in polymer synthesis. The formation of multimode planar waveguides on silicon with a waveguide loss of approximately 1.3 dB/cm at 1.3 mum is demonstrated. Preliminary studies aimed at forming true-time-delay lines are conducted by use of various waveguide lengths in conjunction with an optical heterodyne technique. Waveguide settings equivalent to different true-time-delay lines with a delay time of up to 0.27 ns and a base bandwidth of 25 GHz are demonstrated with a signal-to-noise ratio of 15 dB.

[Effects of cytokines on somatostatin in nude mice bearing human renal cell carcinoma]

We studied the relationship between the production of SS and treatment with cytokines and a new method for the treatment of renal cell carcinoma. 4.4 x 10(6)RCC94616 cells were injected subcutaneously into the back of nude mice. Five groups with TNF, IL-2, rIFN, TNF + IL-2, TNF + rIFN and controls were randomly divided according to the mean diameter of experimental tumor. After the last injection of cytokines, 0.5-0.8 ml blood, 1g tumor tissue, para-tissue and normal tissue were havested respectively. Contents of SS were tested by radioimmunoassay. In the treatment groups with cytokines, the concentration of SS was changed, siginificantly increased in the TNF + IL-2 group (P < 0.01). The effect on distribution of SS by cytokines may also be mediated by the regulation of human immunity and antitumor activity. It may be suggested that the method of TNF + IL-2 + SS is best to treat renal cell carcinoma.

Exercise-induced oxidative stress before and after vitamin C supplementation

Vitamin C (ascorbic acid) was supplemented (1 g/day) for 1 day and 2 weeks in the same subjects. Plasma thiobarbituric acid reacting substances (TBARS) and oxygen radical absorbance capacity (ORAC) before and after 30 min submaximal exercise were measured. Different vitamin C supplementations did not affect resting TBARS or ORAC. Following 30 min exercise, values for TBARS were 12.6 and 33% above rest with 1 day and 2 weeks of vitamin C supplementation, respectively, compared to 46% higher with placebo. ORAC did not significantly change (11%) after exercise with a placebo, nor when subjects were given vitamin C supplements for 1 day or 2 days (4.9% and 5.73%, respectively). TBARS:ORAC, a ratio representing oxidative stress, increased 32% (p < .05) with placebo compared to 5.8 and 25.8% with vitamin C supplements for 1 day and 2 weeks, respectively. It was concluded that exercise-induced oxidative stress was highest when subjects did not supplement with vitamin C compared to either 1 day or 2 weeks of vitamin C supplementation.

Structure of the human gene encoding sterol regulatory element binding protein 2 (SREBF2)

Sterol-regulatory element binding protein (SREBP) 1 and SREBP2 are ubiquitously expressed transcription factors that play key roles in the regulation of cholesterol and fatty acid metabolism. SREBP1 and SREBP2 share approximately 47% sequence identity and map to chromosomes 17 and 22, respectively. The gene encoding SREBP1 (SREBF1) has been cloned and characterized. In this paper we describe the gene structure and 5'-flanking sequence of SREBF2. SREBF2 spans 72 kb and is composed of 19 exons and 18 introns. The locations of the exon/intron boundaries of SREBF2 are remarkably similar to those of SREBF1, but SREBF2 is approximately 2.8 times larger in size. The 5'-flanking regions of SREBF2 and of two alternatively spliced forms of SREBF1, SREBF1a and SREBF1c, were sequenced, and the SREBF2 transcription start site was determined. A perfect 10-bp sterol regulatory element (SRE)-1 sequence was present in the promoter region of SREBF2. No SRE-1 was identified in the 5'-flanking sequences of either SREBF1a or SREBF1c, but several E-box sequences were present in SREBP1c. Thus, analysis of the 5'-flanking regions provides support that these two transcription factors, though similar in their coding sequence and overall gene structure, have different physiological roles. Finally, evidence is presented for the presence of another expressed gene of unknown function located 500 bp upstream of SREBF2.

Complete regression of established murine hepatocellular carcinoma by in vivo tumor necrosis factor alpha gene transfer

BACKGROUND & AIMS

Although tumor necrosis factor (TNF)-alpha possesses a potent antitumor activity, systemic administration of TNF-alpha causes severe side effects. To circumvent this, the efficacy of tumor cell-targeted TNF-alpha gene therapy was investigated.

METHODS

Murine hepatocellular carcinoma (HCC) cells were infected with MNSM-Alb e/p-TNF-alpha retroviruses carrying the murine TNF-alpha gene under the transcriptional control of the murine albumin gene promoter, and antitumor effects induced by TNF-alpha gene transfer were examined in vitro and in vivo.

RESULTS

Although MNSM-Alb e/p-TNF-alpha retrovirally infected HCC cells showed the same in vitro cell growth as parental HCC cells, they lost their tumorigenicity when implanted in syngeneic mice and induced tumor immunity against parental HCCs. The retrovirally infected HCC cells also significantly inhibited the tumorigenicity of previously implanted parental HCCs. Furthermore, intratumoral administration of MNSM-Alb e/p-TNF-alpha retroviruses showed the antitumor effect against established HCCs, resulting in significantly prolonged survival periods. Most importantly, intratumoral implantation of MNSM-Alb e/p-TNF-alpha retroviral-producing cells completely abrogated established HCCs in mice.

CONCLUSIONS

These results indicate the potential efficacy of transferring the TNF-alpha gene via retroviral vectors directly into tumors for gene therapy against HCCs.

The pharmacokinetic and pharmacodynamic interaction between zileuton and terfenadine

OBJECTIVES

The effects of zileuton on terfenadine pharmacokinetics, and the effects of terfenadine alone and the combination on the duration of the QTc interval and the morphology of the TU complex were examined.

METHODS

The study was double-blind, randomized, placebo-controlled, two period cross-over in 16 healthy volunteers. During each period, subjects received 60 mg of terfenadine every 12 h on days 1 to 7 and 600 mg of either zileuton or placebo for zileuton every 6 h on days 1 to 10. Blood samples were obtained on days 7 to 10 and serial ECGs were performed on days -1 and 7 in both periods.

RESULTS

The combination of zileuton and terfenadine was well tolerated. Coadministration of zileuton with terfenadine resulted in a significant increase in the mean AUC and Cmax of terfenadine by approximately 35% and the mean AUC and Cmax of carboxyterfenadine by approximately 15%. The maximum concentration of terfenadine observed in the study was 9.6 ng.ml-1. The addition of zileuton to terfenadine did not result in significant changes in the evaluated ECG-recordings (QTc interval and morphology of TU complex). The difference in means for both maximum and average QTc interval was very small (< or = 2.3 ms), and there were no clinically significant changes in individual values.

CONCLUSIONS

The relatively small pharmacokinetic effect of zileuton on terfenadine metabolism, with no change in the QTc interval, is unlikely to be of clinical significance. The interaction is minimal in comparison to the background variability of the population.

Antioxidant and prooxidant behavior of flavonoids: structure-activity relationships

The antioxidant and prooxidant behavior of flavonoids and the related activity-structure relationships were investigated in this study using the oxygen radical absorbance capacity assay. Three different reactive species were used in the assay: 2,2'-azobis(2-amidino-propane) dihydrochloride, a peroxyl radical generator; Cu(2+)-H2O2, mainly a hydroxyl radical generator; and Cu2+, a transition metal. Flavonoids including flavones, isoflavones, and flavanones acted as antioxidants against peroxyl and hydroxyl radicals and served as prooxidants in the presence of Cu2+. Both the antioxidant and the copper-initiated prooxidant activities of a flavonoid depend upon the number of hydroxyl substitutions in its backbone structure, which has neither antioxidant nor prooxidant action. In general, the more hydroxyl substitutions, the stronger the antioxidant and prooxidant activities. The flavonoids that contain multiple hydroxyl substitutions showed antiperoxyl radical activities several times stronger than Trolox, an alpha-to copherol analogue. The single hydroxyl substitution at position 5 provides no activity, whereas the di-OH substitution at 3' and 4' is particularly important to the peroxyl radical absorbing activity of a flavonoid. The conjugation between rings A and B does not affect the antioxidant activity but is very important for the copper-initiated prooxidant action of a flavonoid. The O-methylation of the hydroxyl substitutions inactivates both the antioxidant and the prooxidant activities of the flavonoids.

Practical Bayesian inference using mixtures of mixtures

Discrete mixtures of normal distributions are widely used in modeling amplitude fluctuations of electrical potentials at synapses of human and other animal nervous systems. The usual framework has independent data values yj arising as yj = mu j + xn0 + j, where the means mu j come from some discrete prior G(mu) and the unknown xno + j's and observed xj, j = 1,...,n0, are Gaussian noise terms. A practically important development of the associated statistical methods is the issue of nonnormality of the noise terms, often the norm rather than the exception in the neurological context. We have recently developed models, based on convolutions of Dirichlet process mixtures, for such problems. Explicitly, we model the noise data values xj as arising from a Dirichlet process mixture of normals, in addition to modeling the location prior G(mu) as a Dirichlet process itself. This induces a Dirichlet mixture of mixtures of normals, whose analysis may be developed using Gibbs sampling techniques. We discuss these models and their analysis, and illustrate them in the context of neurological response analysis.

Construction of retroviral vectors to induce strong hepatoma cell-specific expression of cytokine genes

Continuing advances in molecular biology have provided tools for a promising approach to the treatment of cancer. Among the various strategies of gene therapy for cancer, many are aimed at killing tumour cells indirectly by the induction or reinforcement of a host immune response by gene transduction of various cytokines, major histocompatibility complex or immune accessory molecules. In the present study, we selected the tumour necrosis factor-alpha, interleukin-2 and interleukin-3 genes as potential cytokine genes to induce antitumour effects. We constructed retroviral vectors carrying these cytokine genes under the control of the murine albumin enhancer and promoter and retrovirally transduced these genes into hepatoma and non-hepatoma cell lines. Strong expression of the cytokine genes was induced in transduced hepatoma cells, while no evident expression was detected in transduced non-hepatoma cells. These results demonstrate the hepatoma-specific expression of cytokine genes and imply the feasibility of in vivo gene transfer into hepatomas without affecting any other tissues. Furthermore, these cytokine genes were expressed much more intensively when they were derived from the albumin enhancer and promoter than when derived from the simian virus 40 early region promoter. These results indicate that transcriptional regulatory sequences specific for the target tissues could be preferable to viral promoters for the gene therapy of cancer.

[Pearl and mother-of-pearl powder in health-care]

Based on pharmacological studies in files, mice and rats, the powder of sea pearl (Pteria martensii), mother-of-pearl and freshwater pearl has been proved to have tonic, anti-aging and anti-radiative actions. The effect of the sea pearl and mother-of-pearl powder is higher than that of freshwater pearl powder.

[Angioscopic in-situ arterial bypass for lower extremity revascularization]

The authors' initial experience of angioscopic in-situ arterial bypass of 37 extremities reveals that angioscopy can be used to assist complete valvular ablation and precise location and ligation of tributaries of saphenous vein grafts, avoiding postoperative arterial-venous fistula and warm ischemic injury to grafts. Angioscopy is also used to perform intraoperative completion inspection of the grafts and anastomoses. The designed biocomposite graft and common ostium technique promotes the usage rate of the limited autogenous vein grafts and enlarges the diameter of grafts and blood flow through the distal anastomosis. Because of the above new series of procedures, the extremity salvage rate in this study was 34/37 limbs. During the follow-up period of 2-18 months, all anastomoses were patent. The preoperative ankle and toe pressure of 3.5 +/- 0.2 kPa and 2.0 +/- 0.1 kPa respectively rose to 5.4 +/- 0.1 kPa and 3.8 +/- 0.2 kPa postoperatively. We conclude that angioscopic in-situ arterial bypass surgery is of practical value and specially advantageous in lower extremity revascularization.

Complementation of mutation in acyl-CoA:cholesterol acyltransferase (ACAT) fails to restore sterol regulation in ACAT-defective sterol-resistant hamster cells

A previously described mutant line of Chinese hamster ovary cells, designated SRD-4, fails to synthesize cholesteryl esters, owing to a deficiency in the activity of acyl-CoA:cholesterol acyltransferase (ACAT). These cells also fail to suppress low density lipoprotein receptors or cholesterol synthesizing enzymes in the presence of 25-hydroxycholesterol. In the current studies we show that SRD-4 cells have three defects: 1) a point mutation in one allele at the ACAT locus that changes codon 265 from Ser to Leu, resulting in an inactive enzyme; 2) a silent allele at the other ACAT locus that does not produce detectable mRNA; and 3) a mutation, as yet undefined, that abolishes the ability of 25-hydroxycholesterol to inhibit the cleavage of both sterol regulatory element binding proteins (SREBP-1 and SREBP-2). Correction of the ACAT deficiency by transfection of a wild-type cDNA failed to restore inhibition of SREBP cleavage by 25-hydroxycholesterol, indicating that the ACAT deficiency and the sterol regulatory defect are caused by independent mutations. These data provide further insight into the interplay between ACAT activation and inhibition of SREBP cleavage by 25-hydroxycholesterol, and they indicate that these two processes can be disrupted independently by mutation.

Effect of isothermal radiofrequency radiation on cytolytic T lymphocytes

Previous in vitro studies provide evidence that RF electromagnetic radiation modulates proliferation of human glioma, lymphocytes, and other cell types. The mechanism of RF radiation cell proliferation modulation, as well as mechanisms for effects on other cell physiologic endpoints, are not well understood. To obtain insight regarding interaction mechanisms, we investigated effects of RF radiation exposure on interleukin 2 (IL-2) -dependent proliferation of cytolytic T lymphocytes (CTLL-2). After exposure to RF radiation in the presence or absence of IL-2 cells were cultured at various physiological concentrations of IL-2. Treatment effects on CTLL-2 proliferation were determined by tritiated thymidine incorporation immediately or 24 h after exposure. Exposure to 2450 MHz RIF radiation at specific absorption rates (SARs) of greater than 25 W/kg (induced E-field strength 98.4 V/m) induced a consistent, statistically significant reduction in CTLL-2 proliferation, especially at low IL-2 concentrations. At lower SARs, 2450 MHz exposure increased CTLL-2 proliferation immediately after exposure but reduced 24 h postexposure proliferation. RF radiation effects depended on the mitotic state of the cells at the time of exposure. Comparison of the effects of temperature elevation and RF radiation indicated significant qualitative and quantitative differences.

Antioxidant capacity in different tissues of young and old rats

The antioxidant capacity in heart, liver, lung, and kidney was studied in young (6 months) and old (22 months) male Fischer 344 rats, using the oxygen radical absorbance capacity (ORAC) assay system with two different reactive oxygen species (ROS) generators. The results indicated that liver in old rats had significantly lower peroxyl radical absorbance capacity (ORACROO), units/g wet wt), but higher hydroxyl radical absorbance capacity (ORACOH), units/mg protein) than in young rats. The decreased liver ORACROO in the old rats was mainly due to the loss of cytosol protein, while the increased liver ORACOH in the old rats was a result of an increased resistance of cytosol proteins to the attack of ROS. This conclusion was further supported by the finding that the contribution of nonprotein fraction of liver cytosol to the ORACOH of the cytosol decreased with age. No effect of age was found on either ORACROO or ORACOH in other tissues. The antioxidant capacity for both ORACROO and ORACOH, was usually high in liver and kidney but low in lung and heart.

Short stature and risk of mortality and cardiovascular disease: negative findings from the NHANES I epidemiologic follow-up study

OBJECTIVES

This study sought to examine the relation between body height and incidence of myocardial infarction, coronary heart disease, overall mortality and mortality from cardiovascular disease.

BACKGROUND

An association between short stature and increased risk of fatal and nonfatal cardiovascular disease has been observed in several studies, attracting considerable attention.

METHODS

We used data from the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-Up Study, a prospective study of a large random sample of the U.S. population, to examine the association between height and risk of four end points.

RESULTS

Baseline data were collected from 1971 to 1975 for 13,031 respondents (5,296 men, 7,735 women), and the average follow-up period was 13 years, through 1987. Height was inversely associated with risk of all four of the end points studied in both men and women. However, after adjustment for age and years of education in Cox proportional hazards analyses, the relation no longer existed. Using the same adjustment procedures, persons in the lowest height quintile had no increase in risk compared with those in the highest category. The findings were consistent for men and women, blacks and whites and different age groups.

CONCLUSIONS

Data from this study in a national sample do not support the hypothesis of an inverse height-heart disease relation.